The association between age and nephrosclerosis on renal biopsy among healthy adults.

BACKGROUND

Chronic kidney disease is common with older age and is characterized on renal biopsy by global glomerulosclerosis, tubular atrophy, interstitial fibrosis, and arteriosclerosis.

OBJECTIVE

To see whether the prevalence of these histologic abnormalities in the kidney increases with age in healthy adults and whether histologic findings are explained by age-related differences in kidney function or chronic kidney disease risk factors.

DESIGN

Cross-sectional study.

SETTING

Mayo Clinic, Rochester, Minnesota, from 1999 to 2009.

PATIENTS

1203 adult living kidney donors.

MEASUREMENTS

Core-needle biopsy of the renal cortex obtained during surgical implantation of the kidney, and medical record data of kidney function and risk factors obtained before donation.

RESULTS

The prevalence of nephrosclerosis (> or =2 chronic histologic abnormalities) was 2.7% (95% CI, 1.1% to 6.7%) for patients aged 18 to 29 years, 16% (CI, 12% to 20%) for patients aged 30 to 39 years, 28% (CI, 24% to 32%) for patients aged 40 to 49 years, 44% (CI, 38% to 50%) for patients aged 50 to 59 years, 58% (CI, 47% to 67%) for patients aged 60 to 69 years, and 73% (CI, 43% to 90%) for patients aged 70 to 77 years. Adjustment for kidney function and risk factor covariates did not explain the age-related increase in the prevalence of nephrosclerosis.

LIMITATION

Kidney donors are selected for health and lack the spectrum or severity of renal pathologic findings in the general population.

CONCLUSION

Kidney function and chronic kidney disease risk factors do not explain the strong association between age and nephrosclerosis in healthy adults.

PRIMARY FUNDING SOURCE

National Institutes of Health, U.S. Public Health Service.